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Comments 27301 to 27350:

27301. DSL at 09:46 AM on 12 October 2015
       NASA Retirees Appeal to their Own Lack of Climate Authority
       

       Zoo58: "Risk aversion taken to the extreme, as I qualified it, would indeed stop humanity from doing anything."
       
       Oh, I get it now.  According to your definition of "extreme," anyone who took risk aversion to the "extreme" would be bonkers.  What, pray tell, is your definition of "extreme" risk aversion, and is anyone seriously advocating for it?

27302. zoo58 at 09:05 AM on 12 October 2015
       NASA Retirees Appeal to their Own Lack of Climate Authority
       

       @DSL #65, @PhilippeChantreau #66

       The analogy in this article is poor because one is a known, routine, predictable event that happens every day in America (a car collision), and the other a theoretical disaster scenario that we have never experienced (a rapid climate change disaster).

       All analogies are limited, but this one is particularly bad because the author uses it to draw a connection between Americans buying collision insurance and Americans dramatically changing their energy sources in an attempt to avoid a theoretical problem. The difference should be obvious.

       Admittedly, I struggled to think up a better analogy and picked a rather absurd one (from a scientific perspective), hastily, to try to demonstrate my point.

       Perhaps a better analogy could be postulated in the area of infectious disease. I'm thinking out loud here... we know that high concentrations of humans in cities and frequent travel between them increases the danger of infectious outbreak and that an infectious outbreak could potentially dramatically harm humanity. Should humans cease to travel or cease building cities in an effort to reduce the risk of a large-scale outbreak?

       You might argue "no" (I would) because we are smart enough that we can deal with infectious disease, get them under control, create vaccines or drugs, etc. Climate skeptics can argue analogously that we know enough about our world to mitigate to effects of and adapt to climate change.

       I'm sure that you get my gist, so would either of you care to help think of strong analogy, rather than cut me down?

        

       @PhilippeChantreau #66

       The rest of the post is ripe with straw men, such as "stop humanity from doing anything", and indications of zoo58 lack of knowledge and understanding of the science underpinning the risk analysis he attempts to question.

       Risk aversion taken to the extreme, as I qualified it, would indeed stop humanity from doing anything. There is unknown risk in every action. Scientific understanding of our world makes humans powerful. That power gives us more confidence that we can identify and deal with problems as they arise.

       The risk analysis involved in something as big as climate change (it truly impacts everything on this planet) is really, truly, extremely complex. It's easy to blame others for not understanding it, but do you? What I perceive as cimate alarmists' penchant for character assassination and political posturing over elevating the discussion certainly does not inspire my confidence.

27303. dacama at 08:54 AM on 12 October 2015
       2015: Still No Let Up in Ocean Warming
       

       found it ..thanks for the links.

27304. dacama at 08:47 AM on 12 October 2015
       2015: Still No Let Up in Ocean Warming
       

         Most non scientist live in a degree world, not a joules world. Does that make sense?

27305. scaddenp at 08:28 AM on 12 October 2015
       2015: Still No Let Up in Ocean Warming
       

       The OHC is derived from integration of temperature profile which of course means warmer at top. So when you ask for C, then temperature where? Or perhaps more importantly, why do you ask? If you want to how OHC is derived from ocean temperature measurement, then try this. If you want to know how accurately can you determine OHC given accuracy of measurement and float distribution, then try here with more recent discussion here.

27306. dacama at 07:43 AM on 12 October 2015
       2015: Still No Let Up in Ocean Warming
       

       Hi, what does 17*10^22 joules mean in degress C or K?

       Thank you.

27307. PhilippeChantreau at 04:22 AM on 12 October 2015
       NASA Retirees Appeal to their Own Lack of Climate Authority
       

       I would add that the OP appropriately disputes the fact the individuals mentioned have conducted a true "in depth" assessment of the science. I see nothing in zoo58's showing that their assessment really was in depth. In fact, it is abundantly clear from their declaration that it was not so.

27308. PhilippeChantreau at 04:18 AM on 12 October 2015
       CO2 lags temperature
       

       Thank you Tom, that is much more informative than Tatelyle assertions. The B,D and F graphs in the second figure of yout post are representations of what would be considered reliable ways to determine the presence of a cycle. I had no doubt that this work had been done and that a wide litterature existed on the subject. I am still wondering what is Tatelyle's basis to claim against that existing litterature, perhaps he will tell us more.

27309. PhilippeChantreau at 04:01 AM on 12 October 2015
       NASA Retirees Appeal to their Own Lack of Climate Authority
       

       "Theoretically, evolution could change hummingbirds into bloodthirsty killers at any moment"

       This is one of the most ridiculous statements I've ever read. One ready to throw around such nonsense and in the same post comment on others' analogies being poor is almost funny. The rest of the post is ripe with straw men, such as "stop humanity from doing anything", and indications of zoo58 lack of knowledge and understanding of the science underpinning the risk analysis he attempts to question. I'm unimpressed.

27310. DSL at 01:24 AM on 12 October 2015
       NASA Retirees Appeal to their Own Lack of Climate Authority
       

       Zoo58: "Americans buy insurance for car collisions because they know that car collisions happen, they know how and why they happen, many have been in one before, and they wish to insure themselves against future collisions which they know with a high degree of likelihood will continue to occur."

       Zoo58: "Unlike car collisions, humans do not know that anthropomorphic climate change disaster occurs, what effects it can have, or what factors primarily cause it. We haven't seen it happen before, haven't lived through it, and don't know what the best way to deal with it is. We cannot rationally insure against it because it only exists in our imagination."

       The basis of your post is your claim that we don't understand how the climate works, past, present, and future.  We know quite well why climate change happens.  We know that it has happened in the past many times, and we know that it will happen in the future, regardless of what we're doing now.  We know how the climate system works.  We have direct surface measurement of the greenhouse effect.  Indeed, the theory of the greenhouse effect is one of the most well-established theories science has produced. We know how our contributions to that effect are leading to an accumulation of energy within the climate system.

       Just because you don't understand the science, doesn't mean the science isn't there.  Perhaps you'd be more effective in arguing your position if you actually engaged the science.

27311. zoo58 at 23:33 PM on 11 October 2015
       NASA Retirees Appeal to their Own Lack of Climate Authority
       

       In response to the article...

       This conclusion illustrates a risk management failure which is very common amongst climate contrarians. It's no different than saying "I don't think that I'll be in a car accident, so I won't purchase auto insurance." The average American has a 30% chance of being involved in a serious automobile accident in his or her lifetime, and the odds of very dangerous and damaging climate change are even higher if we continue on a business-as-usual path – in fact that is the most likely scenario.

       That is a very poor analogy. Americans buy insurance for car collisions because they know that car collisions happen, they know how and why they happen, many have been in one before, and they wish to insure themselves against future collisions which they know with a high degree of likelihood will continue to occur.

       Unlike car collisions, humans do not know that anthropomorphic climate change disaster occurs, what effects it can have, or what factors primarily cause it. We haven't seen it happen before, haven't lived through it, and don't know what the best way to deal with it is. We cannot rationally insure against it because it only exists in our imagination.

       A more appropriate analogy would be for Americans to buy hummingbird attack insurance. Theoretically, evolution could change hummingbirds into bloodthirsty killers at any moment. One could argue that anthropomorphic changes to and pressures on our environment cause an increased rate of evolution. Alarmists could claim that the birds are just a couple genes away from devouring us. How many people do you think would buy this type of insurance? None, of course.

       Climate contrarians like these NASA retirees essentially believe that the best case scenario will occur, that the net climate feedback and sensitivity will be near the low end of the possible range, and that we will be able to cope with future climate change.

       This claim is false. As far as I'm aware, NASA retirees have not claimed that they believe the best case scenario will occur. On the contrary, they believe that there's insufficient evidence to determine whether the best or worst case scenario or something in the middle will occur.

       This conclusion illustrates a risk management failure which is very common amongst climate contrarians. It's no different than saying "I don't think that I'll be in a car accident, so I won't purchase auto insurance." The average American has a 30% chance of being involved in a serious automobile accident in his or her lifetime, and the odds of very dangerous and damaging climate change are even higher if we continue on a business-as-usual path – in fact that is the most likely scenario.

       You, on the other hand, appear to be advocating a strong risk aversion which would literally stop mankind from doing anything, if taken to the extreme, and have us walking around on tip-toes afraid of triggering disasters. You are claiming that when you don't know what will happen or whether the outcome will be positive or negative, or, generally, are afraid of change, that you should not act. Mankind would not have advanced nearly this far following such a principle.

       Unfortunately, your principle is actually useless in this case since we're already in uncharted waters. It would've helped stop the industrial revolution before it began, but there's no going backwards. Sequestering carbon and building millions of windmills could be just as harmful, or even more harmful, than continuing to burn fossil fuels. Do we have enough evidence to pick one course of action over the other? Without sufficient evidence, the only difference between the two would be public perception based on political campaigning and, generally, lies: we've been told that CO2 will cause disaster, without proof, and we've been told that windmills will be good, without proof.

27312. zoo58 at 22:50 PM on 11 October 2015
       NASA Retirees Appeal to their Own Lack of Climate Authority
       

       @Glenn Tamblyn #46

       Since the oceans are the primary source of protein for around a billion people, any decline in the biological productivity of the oceans must unavoidably lead to a reduction in available protein.

       Oh really? What if the decline in biological productivity of the oceans lead to a subsequent, even greater increase in the biological productivity on land and available protein from land sources? That would result in an increase in available protein. Can you prove it impossible?

27313. zoo58 at 22:47 PM on 11 October 2015
       NASA Retirees Appeal to their Own Lack of Climate Authority
       

       @JasonB #36

       If 20 unknown people got together and issued a report saying that they aren't convinced that global warming is a problem then nobody would pay it any attention at all. But when those same people attempt to draw attention to their report by pretending that their credentials, and therefore opinion, matter, then they are inviting people to examine those credentials to see whether their opinion really does matter.

       How does one decide whether someone's opinion matters or not? It seems to me that this is far from a trivial problem.

       Here are some possible criteria:
       1. Their opinion matters if it is in agreement with your own.
       2. Their opinion matters if their society or government has deemed them as an "expert".
       3. Their opinion matters if wikipedia says that they're credible.
       4. Their opinion matters if popular opinion says their opinion matters.

       And there are infinite other possible solutions. These ones I've outlined are actually commonly observed in practice, for better or for worse. They are all based on logical fallacies, but it's realistically not possible to hear every opinion, so we some way to be selective.

       Personally, I think you've been far too harsh in your assessment of these NASA retirees. First of all, they explained in their introduction why they feel that their opinion should matter, and I tend to agree with them. As distinguished people with related skills and education who have attempted to conduct a non-biased and in-depth examination of the evidence, why should they not at least be heard? It's plausible that they could have something of value to say that hasn't been heard before, or at least that you could learn something from listening to them.

       In politics, and this issue is highly political in nature, everything goes in terms of getting yourself heard, including appeal to credibility or to your ex-employer's reputation. The climate alarmists are surely guilty of as much with all the disaster scenarios they've come up with. If you're going to complain about it at all, then to be fair you ought to complain about similar behavior by those who lobby for the position that you happen to agree with.

27314. Tom Curtis at 17:01 PM on 11 October 2015
       CO2 lags temperature
       

       PhillipeChantreau @502, using the following image I calculated by pixel count that Antarctic temperature rose to 0 C, at succussive intervals of, 86 thousand, 91 thousand, 112 thousand and 120 thousand years ago (most ancient to most recent).

        

       That takes us back to 400 Kya.  Prior to that, interglacials are cooler, and more frequent.  Using the initial -4 C line to characterize the frequency, we have intervals of 48, 24, 85, 45, 25, 34, 23, 73, 90, 92, 29, 85, 120 thousand years respectively (counting from 800 Kya).  The underlined pair pair obviously show as a single cycle if we use 0 C to characterize successive cycles.

       This simple count between years of particular phases is a crude method to characterize cycles as you know.  If that was what we had to relly on, we would not be able to characterize the frequency of glaciations in any meaningful way.  More advanced techniques show a clear dominance of the 41 Ky obliquity cycle over the last two million years (panels D and F), with the 100 Ky cycle becoming significantly more important in recent times:

       

       Over the last 400 Ky, the 100 Ky cycle has become dominant, with the 41 Ky obliquity cycle still having a greater influence than precession cycles:

       

27315. MA Rodger at 16:56 PM on 11 October 2015
       CO2 lags temperature
       

       tatelyle @500.

       Concerning your little cycling excursion, it is foolish to ignore apsidal precession which is the "difference" you say you are still "not sure about" and whose inclusion yields the net 21.6ky cycle in precession. I can't say I've ever seen a figure for the size of variation in this cycle length. (I imagine it to be small. Axial precession is 25.7+/0.4ky.) This regional/seasonal cycle is of course modulated by eccentricity that leads rise to talk of the 19ky & 23ky signals which when combined achieve the modulated ampitudes. That said, the graphic you reference @500 allows measurement of the length of the three last ice ages yielding (backward from the present) lengths of 119ky, 107ky & 88ky. I'm not sure how this squares with your measurements or with your attempts to fit climate data with the lengths of multiples of precession cycles. Your efforts in this specific matter appear to be mainly driven by what is a well-known incongruity. That is that the high levels of variation in NH insolation due to orbital precession have small climatic reactions while the low levels of variation due to global orbital eccentricity have very large climatic reactions. This finding is decades old so try not to get too bogged down in it - it is well trampled ground.

       Concerning your resurrection of the incoherence you presented @498, the sentence at which I gave up all hope of identifying your meaning was "The exclusivity of NH insolation triggers strongly suggests that albedo is the key factor and the key feedback regulating Interglacials." I'm afraid that substituting the word "primary" for the word "key" doesn't make your meaning any clearer.

27316. PhilippeChantreau at 02:37 AM on 11 October 2015
       Satellites show no warming in the troposphere
       

       They'll just start a new "pause" in 2015, no worries. It's not like their audience is critical anyway. You can say anything to someone who wants to believe a certain way, as long as it goes that way, no matter how unreal.

27317. PhilippeChantreau at 02:15 AM on 11 October 2015
       CO2 lags temperature
       

       That's a lot of different cycles mentioned here. What are the statistical criteria to establish the existence of a cycle? What method did you use to identify the cycles? Does this fine cycle discrimination have any reference in the scientific litterature? 

27318. tatelyle at 21:16 PM on 10 October 2015
       CO2 lags temperature
       

       >>Rodger
       >>I am assuming that you have not yourself "counted
       >>the years." For my own part, I have in the past been
       >>content to take the word of others for the recent ice
       >>age cycles being 100,000 years long, this being a
       >>well-known and unchallenged finding.

       If you look at post 479, you will see that the gap between recent interglacials is 109 k years, not 100 k years. And this is supported by this alternate graphic of the Vostok data. And here you will see two 109 k year cycles,* preceded by two 88 k year cycles:**

       https://i1.wp.com/www.brighton73.freeserve.co.uk/gw/paleo/400000yearslarge.gif

       Quite clearly, the Interglacials are following the Milankovitch warming in the NH, with intervals of 4 cycles and 5 cycles (for the last two cycles).

       * A 113 k cycle, and a 109 k cycle.

       ** The difference from my previous post is caused by some confusion over the length of the precessional cycle. It is given as 25,800 years in many texts, but if you look at these graphs they clearly show a 22,000 year cycle. I am not sure why the difference. I simply counted the precessional cycles, rather than counting the years. But if the precessional cycle really is 22,000 years, which is not how I understood it, then the Ice Age cycle lengths are shorter, but still not equal. But there are still two different cycle lengths to Ice ages, and averaging them is not a valid methodology.

        

       >>I am at a loss with what you mean by the
       >>phrases "key factor" and "key feeback"

       The primary feedback. It is highly unlikely that all feedbacks are equal in effect. My point was the albedo feedbacks are probably more important than CO2 feedbacks, because Interglacials react to high latitude NH forcing. That strongly suggests that forcing and feedbacks are a result of changes in albedo, rather than a function of CO2.

        

       >>The full mix of forcings that result in ice age cycles is not
       >>yet fully determined which makes any informed response
       >>to you a tad harder still.

       I thought the 'science was settled'?

       Moderator Response:

       [DB] Inflammatory tone snipped.

27319. longjohn119 at 18:35 PM on 10 October 2015
       The Republican Party stands alone in climate denial
       

       Comparing Republicans to actual Conservatives in other nations is pure folly because Republicans are Fictional Conservatives. Any notion that their ideas are Conservative is as fictional as the WMD's in Iraq ..... True Conservative Stalwart Barry Goldwater predicted and warned us about exactly what we are seeing today

       Mark my word, if and when these preachers get control of the [Republican] party, and they're sure trying to do so, it's going to be a terrible damn problem. Frankly, these people frighten me. Politics and governing demand compromise. But these Christians believe they are acting in the name of God, so they can't and won't compromise. I know, I've tried to deal with them.

       - Barry Goldwater, November 1994

       Shortly afterward he told the Republican Leadership

       "Do not associate my name with anything you do. You are extremists, and you've hurt the Republican party much more than the Democrats have."

       I'm sure this will be deemed too political but you cannot solve a problem by being nice and ignoring it's cause and history

27320. Tom Curtis at 17:58 PM on 10 October 2015
       2015: Still No Let Up in Ocean Warming
       

       uncletimbrob @4, I, on the other hand, have seen deniers use claimed assymptotic behaviour as an argument.  There is the claim that Sea Surface Temperatures have an upper limit just over 30^oC; and the claim that the greenhouse effect is saturated.  They do not use the language of assymptotes, but clearly the idea underlies their thinking.  Having said that, I do not think a vertical assymptote in OHC, that forces greater and greater increases in OHC with less and less forcing, will be appealing to deniers.  Nor is if physically possible (apparently contrary to RobH @2).  

27321. Leslie Graham at 11:13 AM on 10 October 2015
       Satellites show no warming in the troposphere
       

       Can anyone estimate when the RSS data is likely to show peak reaction to the current El Nino?

       So far as I can tell, during the '98 event SST's peaked in around Nov/Dec 97 and RSS peaked around March/April. To judge from the current (9th Oct) very strong WWB west of the dateline this event is not going to peak until around Dec/Jan. So am I right in assuming that the RSS data is likely to break the '98 peak temperature record sometime around April 2016?

       I'm curious as to how the denial industry will spin a new record high temperature on the RSS graph.

27322. uncletimrob at 17:59 PM on 9 October 2015
       2015: Still No Let Up in Ocean Warming
       

       @RobH  I've not seen assymptotic behavior used by conrtarians - why did you alert them to it?

27323. scaddenp at 12:39 PM on 9 October 2015
       2015: Still No Let Up in Ocean Warming
       

       It is not an asymptote - just an illusion from noisy data. Look at the blue and black lines. Expect to see the vertical scale expand however.

27324. RobH at 12:21 PM on 9 October 2015
       2015: Still No Let Up in Ocean Warming
       

       There is an asymptote in Figure 1 - which looks incredibly scary.  Would any of the experts monitoring this site provide comment?

27325. michael sweet at 09:43 AM on 9 October 2015
       Global warming's one-two punch: extreme heat and drought
       

       Kanon,

       Most water cycles through the weather system in a few weeks.  Temperature changes are really a decadal change (or longer) for a significant effect.  The water will be able to stay in equilibrium with the temperature.

       We are still likely to see many unexpected changes in the weather system as AGW progresses. 

27326. XRAY1961 at 03:18 AM on 9 October 2015
       Skeptical Science reader survey - thanks for your feedback!
       

       Thank you for the update.  I appreciate the direct answer to my question in the survey regarding updates to the rebuttals and I look forward to seeing the updated information.

27327. kanon at 01:05 AM on 9 October 2015
       Global warming's one-two punch: extreme heat and drought
       

       Is there a delay effect where higher temperature reduces rainfall while net evaporation increases due to a higher saturation point?  In other words, could we have a period of drought while the water vapor increases and then a new precipitation pattern is formed?  Thanks

27328. MA Rodger at 23:34 PM on 8 October 2015
       CO2 lags temperature
       

       tatelyle @498.

       Thank you for your response to #495. It is always refreshing to meet new ideas.

       I am assuming that you have not yourself "counted the years." For my own part, I have in the past been content to take the word of others for the recent ice age cycles being 100,000 years long, this being a well-known and unchallenged finding. Thus your contrary assertion would certainly tumble much scientific work, for example, Abe-Ouchi et al (2013) which is titled "Insolation-driven 100,000-year glacial cycles and hysteresis of ice-sheet volume." That is to say, your assertion would certainly tumble such work if your assertion were based on a shred of truth. So I did some measuring. I see no evidence for a 102ky/128ky cycle. My measurements are cursory but I feel they are adequate. They show cycles in orbital eccentricity to average 97ky(s.d. 7ky) and the ice age cycles to average 100ky(s.d. 10ky). I conclude that your bold assertion "equalls" wrong presumption.

       I would be interested to learn why you assert "There are always greater and lesser feedbacks." Certainly, as a general rule systems are driven by simple mechanisms rather than complex ones but it is well known that 'general rules' do not apply "always".

       Sadly, the remainder of your comment tumbles into incoherence. I am, for instance at a loss with what you mean by the phrases "key factor" and "key feeback" or what you mean by 'regulating interglacials.' You rely on a finding of your own calculation (presented less than confidently "correct me if I am wrong" @494 ) but you may have already noted @499 that I refute that "back of a fag-packet calculation"@494. Indeed (and here adding substance to the moderation Response@494), within the ice age dynamics it would be a surprise if any realistic calculation of Δ(NH ice albedo forcing) were greatly different to the Δ(global ice albedo forcing), which is the value presented by Hansen & Sato (2012): a surprise as all here do appear in agreement that these two quantities are effectively equivalent. The other 'back of a fag-packet calculation' you present (@498) is more of a mystery despite the list of assumptions provided. It is not at all clear by what means you convert peak 65ºN Milankovitch insolation figures for July into a figure for "over the whole interglacial" or indeed how you define that term "over the whole interglacial". I think these exemplars of the error & the lack of precision that you have managed to entwine together @498 adequately illustrate the level of incoherence @498.

       To paraphrase my comment @492 - You create bizarre answers but that is because you appear set on answers that are simpler than the situation merits. Do also bear in mind that the full mix of forcings that result in ice age cycles is not yet fully determined which makes any informed response to you a tad harder still.

27329. uncletimrob at 17:56 PM on 8 October 2015
       2015: Still No Let Up in Ocean Warming
       

       Oh God, I can just see the comments of the contrarians on those graphs!  And, I'll bet I can tell anyone which parts of the graphs will be selected to show that "the books have been cooked' or some such rubbish

       Anyway back to normality - thanks for an informative post

       Tim

27330. Glenn Tamblyn at 15:37 PM on 8 October 2015
       It's a natural cycle
       

       billev

       There are other factors to think about when evaluating what the temperature record may or may not mean

       1. It only represents warming of the atmosphere and this is only around 2% of the total energy being added to the climate. Around 93% of the extra heat is going into the oceans. And at the same time there are energy exchanges between the oceans and the atmosphere. Given the much larger size of the oean sink, even a small change in the size of this exchange could significantly impact atmospheric temperatures while being a trivial change in the oceans heat content. Even modest changes in circulation patterns could significantly alter air temperature trends
       2. Data from earlier than 1957 doesn't give coverage of the whole world and prior to the 1920's essentially both the polar regions were absent. Other evidencde suggests there may have been a localised warming occuring in the Arctic during the 20's and 30's at exactly the same time that measurement coverage in the northern polar regions was in flux - not an ideal situation.
       3. There is a recognised bias in the dataset from the period around WWII associated with changes in the nationality of the shipping fleets taking sea surface temperature measurements - the main contributor to the temperature record - due to the war.
       4. Looking at temperature trends for days vs nights also suggest that there was a stronger daytime cooling during the 40's to 70's period than nighttime which may have continued warming. If different tims of day are responding differently that suggest multiple factors at work when the sun is shining and not - warming due to CO2 over the entire day counteracted by daytime cooling due to increased air pollution is a possible explanation.

       The take-away from this is we can't make a judgement about what was going on back then without putting all the pieces of data we have together like a jig-saw puzzle rather than focusing  on just one type of data set. And recognising that when we look back to the mid 20th century and earlier many of these datasets are significantly missing/sparse - ocean heat content for example.
       
       What we have now is that all measures of what is happening - ocean heat, sea level, ice sheet melt, land temperatures and atmospheric temperatures are all pointing to warming.

       To be a natural cycle the data would need to show different masurements indicating opposite trends as energy cycles between different internal parts of the system. If air temperatures were rising as ocean heat was falling (and the size of the changs was comparable) then we might suspect a natural cylical flow between the two.

       The basic conservation Laws - Conservation of energy, mass etc. - require that any natural internal cycle between components of the system produce opposite cycles in the different parts. If all parts of the system are moving in the same direction then internal cycles can't explain it.
       
       This doesn't rule out external cycles such as changes in the Sun's heat output - separate evidence mitigate against them - but all factors moving in the same direction does mitigate against internal cycles.
       
       Basic premise, as pointed out by others. Cycles don't just happen, they always have causes. And those causes must satisfy the conservation laws.
       
       To paraphrase 'S#!t doesn't just Happen! It is Caused'.

27331. Paul.H at 12:23 PM on 8 October 2015
       Skeptical Science reader survey - thanks for your feedback!
       

       lol at bitter denier comments, because what else is here to do at this point.

27332. MA Rodger at 09:59 AM on 8 October 2015
       CO2 lags temperature
       

       Tom Curtis @496.

       I think you are asking for more than tatelyle is capable of providing. Consider his track record down this thread & make your own judgement. Below I collate the interchange that led to your comment @496. It is interesting how often tatelyle actually argues against what is his own misunderstanding. Even tatelyle's attack on Hansen & Sato (2012) leads him to his back of a fag-packet calculation @494 which looks to me as though he perhaps also mistakenly multiplied by the number of cigarettes in the packet, because with the model tatelyle tries to use the albedo effect seems to confirm Hansen & Sato. But, of course, that would never do because with tatelyle it is ABC - anything but carbon.

       ☻ TC@481 "(M)ilankovitch cycles can only significantly effect global temperatures if there are, not just feedbacks, but differences in th feedbacks that depend on location and season."

       ☻ tl@487 to TC "(You say ) Milankovitch cycles require feedbacks?

       I understand all your arguments, that overall insolation cannot change much. However, the critical season and region for Ice Age modulation is the NH summer at northerly latitudes, because of the large NH landmass, as you say. It is this insolation that will decide whether the winter ice sheets melt, and so it is this region that will modulate Ice Ages."

       ☻ TC@489 to tl "Causing "winter ice sheets" to melt is a feedback. Further, it is a seaonal and regional feedback. If the seasonal and regional feedbacks in all areas and seasons were equally strong, then that feedback would be balanced by other, opposite feedbacks."

       ☻ tl@490 to TC "(you say) feedback would be balanced by opposite feedbacks because the changes in global annually averaged insolation balance out? But that is not true is it? - because as you said the NH and SH are very different, and so there is no 'balance' or equivalence between them.

       So although the Ice Age becomes a global phenomina, it is triggered and forced by northern hemisphere Milankovitch forcing and only by northern hemisphere forcing. That is an indisputable fact."

       ☻ MAR@492 to tl "Answers on how ice ages happen are not simple. So are you then still happy to assert "So although the Ice Age becomes a global phenomina, it is triggered and forced by northern hemisphere Milankovitch forcing and only by northern hemisphere forcing. That is an indisputable fact."? (My bold)

       ☻ tl@493 to MAR "I was trying to counter the previous statement by Tom that 'Causing ice sheets to melt is a feedback'. Sorry, that is wrong. There needs to be a trigger, before feedbacks can assist in that process. Tom was trying to undermine the value of NH Milankovitch forcing, and I think I have successfuly countered that argument."

       ☻ TC@496 to tl "The brazen assertion that "Causing ice sheets to melt is a feedback" is wrong evidently needs some clarification."

27333. PhilippeChantreau at 09:50 AM on 8 October 2015
       The Republican Party stands alone in climate denial
       

       "climate is giving the US on average more of a flogging than most other places"

       I'm really not so sure about that. Last week-end 20 persons died in Southern France (in the region often referred to as the Riviera or "Cote d'Azur") because of extreme rain and floods. Some were stuck in their garage, a family was trapped in their car in a tunnel that filled with water. Rescue workers logged over 1000 interventions with 23 helicopter retrievals.

       It didn't make the news in the US, too busy about their own catastrophic floods in the South-East. Perhaps the good legislature there can also ban the word "flood" from public discourse, like they did with "accelerating sea-level rise".

       It is rather ironic, and yet denial is as entrenched as ever in the so-called conservative part of the population. It seems that no amount of evidence and no severity of adverse event can bring them back to reality. Meanwhile, we are splitting hair about the meaning of Hansen's exact words in 1988 or some other piece of nonsense. I am becoming more and more convinced that this experiement will have to run its full course. Maybe that end result will be beneficial after all is said and done.

27334. scaddenp at 08:43 AM on 8 October 2015
       The Republican Party stands alone in climate denial
       

       "climate is giving the US on average more of a flogging than most other places"

       It is? I dont think ramifications of drought in California quite on same scale as drought in Syria. The same could be said of many other weather events exacerbated by climate change.

27335. scaddenp at 06:21 AM on 8 October 2015
       It's a natural cycle
       

       I would reinforce what Rob said. You will find it very hard to get people to accept the idea of a natural cycle that violates conservation of energy. Temperatures change for a reason.

       However, on an unevenly heated planet that is mostly covered in water, there are natural variations in surface temperature from the ocean. You dont need much heat loss from the ocean upper layer to heat the air quite a lot. Rather than look at surface temperature, try looking at ocean heat content. eg see here Changes to incoming solar (eg volcanoes) are reflected in the wobbles. The steady upward trend however is a diagnosis of long term energy imbalance - the increase in GHG.

       So to claim "its a natural cycle", then you need to be pointing to either an externality (eg change in volcano screening or change in solar input), or an internal variation - ocean-atmosphere heat exchange. You can see latest OHC here. Externalities cant explain post-1970 heat rise, so must be internal? Nope. Claiming heat is from oceans while ocean heat is rising is voodoo climatology.

       That said, if your "skepticism" about AGW is based on political values or group identity, then I doubt anything posted here will change your mind.

27336. Rob Honeycutt at 03:46 AM on 8 October 2015
       It's a natural cycle
       

       billev... No one has any obligation to satisfy you with their explanations. The explanations merely need to be correct, which they are. Previous commenters have given you very clear and accurate explations as to each of the various time periods. No one is trying to hide anything. 

       I believe I stated this before: Warming doesn't just happen for no reason. It is a response to a radiative forcing of one sort or another. Prior to 1940, warming was a combination of increasing human emissions of CO2 and other natural factors. Post 1940 was likely due to increasing aerosol emissions due to rapid industrialization. Post 1970 was when we cleaned up much of those aerosol emissions which unmasked the underlying CO2 forcing.

       Just because you can't understand or manage to accept these explanations does not in any way reflect on their accuracy.

27337. billev at 03:33 AM on 8 October 2015
       It's a natural cycle
       

       Regardless of all of the mind reading about my intentions,   my original post only pointed out what I observed in the NOAA mean temperature record from 1880 until around 2000.  I pointed out that I perceived two periods of warming and two periods of pause in warming during that period.  The replies to my original post have been an attempt to explain away the pauses using several explanations none of which satisfy me as being realistic.  What I do note is a desperate need to hide the pauses or avoid any involvment of nature in the pauses so plainly shown in the NOAA graphs. 

       Moderator Response:

       [Rob P] - The warming from 1910-1940, a time of weak anthropogenic (human-caused) forcing, matches the warm (positive) phase of the Interdecadal Pacific Oscillation (IPO) - the largest natural multidecadal oscillation in the climate system. This is the dominant 'natural factor' that other replies in this comment thread have alluded to. The cooling mid 20th century occurred during the cool (negative) phase of the IPO.

       

       So the cooling back then wasn't only down to increased industrial aerosol pollution blocking/scattering some of the incoming sunlight, the IPO also played a part. Perhaps the most notable aspect of the IPO is that its influence on global temperature has diminished over time - it's being overpowered by the greenhouse gas forcing. 
       
       Some useful reading here:

       1. Early twentieth-century warming linked to tropical Pacific wind strength - Thompson et al (2014).

       2. Drivers of decadal hiatus periods in the 20th and 21st centuries - Maher et al (2014).

       3. The influence of anthropogenic aerosol on multi-decadal variations of historical global climate - Wilcox et al (2013). 

       [JH] You are now skating on the thin ice of excessive repetition which is prohibited by the SkS Comments Policy.  

       Please note that posting comments here at SkS is a privilege, not a right.  This privilege can be rescinded if the posting individual treats adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.

       Please take the time to review the policy and ensure future comments are in full compliance with it.  Thanks for your understanding and compliance in this matter.

27338. tatelyle at 03:28 AM on 8 October 2015
       CO2 lags temperature
       

       >>The trigger is synchronised to the 100ky orbital eccentricity.

       No it is not.  Count the years.  The trigger is synchronised in the later Ice Ages with increasing NH Milankovitch insolation, which is directly linked to the 25,700-year precessionay cycle.  So the cycle length is either 102,000 years or 128,000 years, as you can see.  

       Big difference. Wrong cycle equalls wrong explanation.

       >>'which is the primary feedback' is presumptive.

       Not sure why. There are always greater and lesser feedbacks. But now we have identified the correct cycle that regulates Interglacials, we are in a better position to identify the primary feedback.  And since Interglacials are SOLELY triggered by increased NH insolation events we can be pretty sure that CO2 is not the primary feedback.  If Co2 was thenorimary feedback, Interglacials could also be triggered by SH warming.  But they are not.

       The exclusivity of NH insolation triggers strongly suggests that albedo is the key factor and the key feedback regulating Interglacials. And as we know the actual high latitude insolation and the actual ice sheet insolation increase is an order of magnitude greater that CO2 can manage.

       Actual insolation increase 90 wm2 on the ice sheets (over whole Interglacial).

       Actual albedo insolation increase 170 wm2 in northern latitudes (over the whole interglacial)

       (Assumptions.  NH insolation 460 wm2.  Cloud albedo -80 wm2. Increase in albedo between ice and vegetation 50% or 170 wm2.)

       So which is going to be the primary feedback?  CO2's 4 wm2, or albedo's regional 170 wm2?

27339. bozzza at 19:30 PM on 7 October 2015
       CO2 lags temperature
       

       If a gun is fired it doesn't mean the target will be hit.

       Many things happened to make the gun fire and many things happened after the gun was fired.

       This is complexity: now measure it!

       ("Um, What should we measure first and how?")

27340. RobH at 14:15 PM on 7 October 2015
       The Republican Party stands alone in climate denial
       

       ... of course, there is schaudenfraude in that the climate is giving the US on average more of a flogging than most other places.  Like the gun issue, it is a interesting to see outright NRA supporters ending up gun victims.  Sad though for the rest of the population.

27341. RobH at 14:03 PM on 7 October 2015
       The Republican Party stands alone in climate denial
       

       Not so for Australia.  Until the ousting of denialist prime minister Abbott, the Liberal/National government posted CO2 reduction strategies that are, and still are, nothing more than a fig leaf to cover entrenched denialism.  Attempts to dismantle government agencies created by the previous Labor government to foster sustainable development were only stopped in the senate.  In other cases, executive orders shut down funding for wind turbines.  Statements to the United Nations in regard to Australia's climate change policy were nothing less than obfuscation if not downright lies.  Our new prime minister Turnbull is fully up to speed with climate change but was originally replaced by Abbott over his positive stand onclimate change - so now has to play to the extreme right wing if he wants to keep his job.  On this basis, Australia needs to get a flogging when it appears with its "fig leaf" policies in Paris in December.

27342. hankspage at 10:41 AM on 7 October 2015
       Skeptical Science reader survey - thanks for your feedback!
       

       Didn't see the notice about the survey or would have replied. As someone who lives in Texas I'm really outnumbered when it comes to the deniers. I check this site every day or two to find news and often to find the real truth when the deniers send me some propaganda. They get upset when I reply with documented evidence I've found on this site to some climate change myth they are trying to pass as a fact.

27343. airscottdenning at 05:19 AM on 7 October 2015
       The Republican Party stands alone in climate denial
       

       Extreme partisan polarization (the team sports analogy described in comment #1 above) combined with the enormous role of monetary contributions have amplified the absurd anti-science rehtoric of the political right in the US compared to that of other countries.  

       There's also the problem that professional climate communication has settled on a three-part message that fails spectacularly with these audiences: "it's real, it's us, scientists agree." This message works well with some people, but each part is challenged by "Team Red" with some success in public opinion. 

       People don't warm the climate; heat warms the climate! We see this every day (vs night) and every summer (vs winter). There's zero disagreement about this, even with conservative audiences.

       Then we can move on to solutions. The Team Red position is that free market economies are fundamentally weak and must be subsidized by digging free stuff out of the ground. They argue that capitalism is powerless to solve an existential problem and has to roll over in the face of rising temperatures, water shortages, and rising seas. This is not consistent with free-market idelology. It is pathetic defeatism, and real conservatives need to call it out.

       The political right must not bet its future on the premise that "heat doesn't cause changes in temperature." Rather, it must engage in a vigorous and full-throated debate that the free-market can offer the BEST solutions to the world's biggest problem. Team Red has been AWOL on advocating for free-market solutions. Not only is this a LOSER position, it also guarantees that actual climate solutions will come from Team Blue. 

27344. ubrew12 at 05:07 AM on 7 October 2015
       The Republican Party stands alone in climate denial
       

       Cartoonist Mike Luckovich's cartoon take on the probable cause of GOP climate denial.

27345. Kiwiiano at 04:58 AM on 7 October 2015
       The Republican Party stands alone in climate denial
       

       Hopefully the record rainfalls in Carolina and the droughts & wildfires in the west will undercut their popularity as folk realise what is happening, assuming of course they actually need voters to turn out for them. The American political system is so disfunctional & corrupt they may not be needed.

27346. Rob Honeycutt at 23:55 PM on 6 October 2015
       Tracking the 2C Limit - August 2015
       

       Thms... You know, you're absolutely correct. I forgot to pull down the data in my spreadsheet. When I did that I got the same answer as you. I'm still getting used to my own process. :-)

27347. Thms at 23:33 PM on 6 October 2015
       Tracking the 2C Limit - August 2015
       

       Hi Rob!
       
       We have almost exactly the same.
       
       Your "In July we stood at 1.060C ..." is the "problem".
       
       July means IMHO the current 12 month (July and 11 months back). I take July as starting month and additional the last 11 months.
       
       You take for July the data from June and additinal the last 11 months.
       
       
       I'm afraid my English is a bit rusty.

27348. Rob Honeycutt at 21:51 PM on 6 October 2015
       Tracking the 2C Limit - August 2015
       

       Thms... I'm using the exact same data. Not sure why you getting a different answer.

27349. Tom Curtis at 21:44 PM on 6 October 2015
       CO2 lags temperature
       

       tatelyle @493:

       "I was trying to counter the previous statement by Tom that 'Causing ice sheets to melt is a feedback'. Sorry, that is wrong. There needs to be a trigger, before feedbacks can assist in that process. Tom was trying to undermine the value of NH Milankovitch forcing, and I think I have successfuly countered that argument."

       The brazen assertion that "Causing ice sheets to melt is a feedback" is wrong evidently needs some clarification.  Specifically, you commented on the origian articles claim that:

       "In other words, increasing CO2 levels become both the cause and effect of further warming. This positive feedback is necessary to trigger the shifts between glacials and interglacials as the effect of orbital changes is too weak to cause such variation."

       (My emphasis)

       The inclusion of the two sentences is necessary to establish context, specifically that the articles claim about feedbacks related not to icesheet melt directly, but to the warming of the climate, ie, the increase in Global Mean Surface Temperature.

       With regard to the claim in the article, you asked the question:

       "The article states that CO2 is a feedback that assists Milankovitch cycle warming / cooling. Many commentaters here have also stated that Milankovitch influences are weak, and need a feedback to have any effect on climate. Can someone explain why?"

       (My emphasis)

       Given the clear context of the claim you were discussing, you were asking for an explanation as to why feedbacks must be inferred to explain the "... warming of the climate", ie changes in GMST.  At least, if you were not, you were instead indulging in the rhetorically odious, and vacuous tactic of bait and switch.  But, just to reinforce it, you yourself clearly reference effects on climate.  Once again, ice sheet melt is not a change in climate, still less the more precise change in GMST required by context.

       Formally, A is a feedback on B if and only if:

       1)  A is not B;

       2)  Changes in B cause changes in A; and

       3)  Changes in A cause changes in B.

       As such, it seems straightforward that melting of icesheets are a feedback on global GMST.  Specically, melting of ice sheets are not GMST (clause 1); changes in GMST can cause icesheets to melt (clause 2); and melting of ice sheets changes GMST by changing albedo (clause 3).  Ergo, the only way you can deny that the melting of ice sheets is a feedback in the context of this discussion is to deny that we are talking about GMST (ie, genuinely be indulging in the odious tactic of bait and switch), or deny that either the melting of ice sheets can effect GMST, or that changes in GMST can effect the melting of icesheets.  Neither of the later two seems at all probable.  The first (denying that melting icesheets effects GMST flies in the face of all the ice core evidence), while denying the second amounts to denying that the changes of state of water are controlled by temperature.

       I require urgent clarrification of what claim exactly you are basing your denial that melting of ice sheets is a feedback.  Are you employing bait and switch tactics (ie, discussing feedbacks on the melting of ice sheets rather than as required by context and your prior statements, feedbacks on changes in GMST) - or are you making extraordinary claims without evidence (ie, denying either of the two relevant cause/effect relationships).

       I also request that other commentors not engage with Tate until he has clarified what is the exact basis of his absurd rejection that ice sheet melt is a feedback.  Prima facie, and absent clear clarification such, engagement is futile in that he is merely using rhetoric to mask confused thinking rather than honestly engaging in the discussion.

27350. MA Rodger at 19:34 PM on 6 October 2015
       CO2 lags temperature
       

       tatelyle @493.

       Can we then be clear then - Ice ages are triggered. Following this they are forced by feedbacks.

       Concerning the trigger, the evidence suggests the trigger is NH insolation, in the late pleistocene this being synchronised to the 100ky orbital eccentricity cycle while in the early pleistocene this was synchronised to the 41ky orbital obliquity cycle. The trigger mechnanism is thus probably more a question of what primes the trigger than what the trigger happens to be.

       Nothing about ice ages is straightforward. Even the events that began the ice age cycles at the end of the pliocene, events bound up with the closing of the Panama isthmus, events which caused both warming and cooling, even those events are not simple and obvious.

       So to say "the trigger for Interglacials was NH Milankovitch ..., I think this is a correct statement." is not an end to the 'trigger' story. (Note you yourself @493 are speculating that dust was not present 170kybp preventing an interglacial occurring but was 150kybp for the creation of the Eemian.)

       Then concerning feedbacks, once the ice age is in progress, the idea that feedbacks will drag the climate through the cycle is perhaps simple to grasp. But, while feedbacks can be listed out, the mix of feedbacks cannot be determined accurately enough to be certain of that mix. Thus your question @493 'which is the primary feedback'? is a bit presumptive, even as a genuine question. Why should there be a single primary feedback? All the evidence points to there being no single primary feedback. So the answer you yourself give to a misplaced rhetorical question "And I think the obvious answer is albedo."is not speculative. It is wrong.

       Thus the moderator response pointing the need for reference (that you protest about @494) is no great surprise to me.

       And the remainder of #494 reminds me so much of why I wrote the first paragraph @492. I would humbly suggest you revisit it.

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